Described below is a method and an apparatus for configuring mode timers to control a probability that a user equipment device UE, such as a mobile station is in a power saving mode to adapt the user equipment UE to characteristics of a shared channel and packet service.
The power consumption of user equipment (UE), such as a mobile device, is a series issue for wireless data transmission. In existing communication systems, such as the global system of communications (GSM), WCDMA, CDMA 2000, IEEE 802.11 and IEEE 802.16 associated protocol states are defined to allow further equipment to work in a power saving mode. A corresponding transition between different states of operation, i.e. operation modes, are triggered by mode timers or signalling. An important requirement for the evolution of a third generation (3G) radio communication system like UMTS is an efficient use of battery power as well as short latency of state transition of the user equipment UE or terminal. A known way to save battery power and to trigger state changes from an inactive to an active state and vice versa is to use a paging mechanism with which the user terminal periodically monitors the paging channel of a base station BS in order to identify whether it has to turn on its receiver in order to fetch transmitted data. When a DRX (Discontinued Reception) cycle length mechanism is applied together with the paging mechanism the use of the battery power is improved allowing a trade-off between activation time and power consumption at the user equipment terminal. In known systems, the control of state transition doesn't jointly consider the traffic characteristics and power conditions of the UE. Entering sleep mode frequently and supplying a long DRX cycle can lead to good power saving effect, but this doesn't make much sense for power insensitive UE and may degrade the quality of service of delay sensitive UE. On the other hand, making the DRX cycle length shorter results in a faster draining of the terminal's battery. Especially in a situation where the delay requirement of the traffic is not strict this is highly ineffective.
With the evolution of wireless communication systems toward wide-band all IP networks packet based services will dominate future radio services. In order to accommodate the busty characteristic of packet services and guarantee quality of service (QoS), protocol states and related timers have to be designed carefully, so that the requirements on some performance metrics, such as source utilization, signalling overhead, delay of packet delivery and power saving factor can be guaranteed or a good trade-off among these performance metrics can be achieved.
In known systems, the configuration of mode timers is employed in a dedicated data transmission channel. However, communication systems of the evolved third generation, such as 3GPP long term evolution (LTE), and WiMax has shared channels to support most of the services including real time services.